Internal combustion engine apparatus with fuel filter for motor vehicle

ABSTRACT

The fuel-filter housing for an automotive vehicle is built into an air filter or the fuel tank or the fuel-tank venting filter so that its cover is available on an outer wall of the component into which it is built for removal and replacement of the filter cartridge. Any leakage is collected in the component in which the filter housing is mounted.

FIELD OF THE INVENTION

The present invention relates to a device or system for supplying fuelto the engine of a motor vehicle and, more particularly, to an internalcombustion engine apparatus provided with a fuel filter for a motorvehicle.

BACKGROUND OF THE INVENTION

A typical motor vehicle driven by an internal combustion enginecomprises, in addition to the engine, a fuel filter which can have afuel filter housing of a synthetic resin material or plastic and areplaceable filter cartridge. The fuel supply system can additionallycomprise a fuel pump, a fuel tank and a fuel line for delivering thefuel via the pump to the internal combustion engine.

The engine system can also comprise an air-supply system for deliveringthe combustion air to the engine. The air-supply system can comprise anair filter and an air duct. The fuel filter housing is traversed by thefuel under the pressure of the pump and, when the pump is energized orswitched in, the fuel filter housing is under a superatmosphericpressure.

The vehicle may be provided with a tank-venting system for drawing fuelvapor out of the tank. In that case the air-supply system will, for thepurposes of this application, be understood to also include thecomponents of the tank-venting system. The term "system" is used hereinto refer to all of the components provided for tank venting, air supplyand fuel supply according to the invention.

In the past the fuel filter has been provided along the fuel line in ahousing connected on one side to the fuel line and on the other side tothe fuel injectors or carburetor. The housing was formed with a coverwhich could be removed to enable replacement of the filter cartridge.

For safety purposes and to avoid contamination of the environment, thefilter housing had to be secure against leakage and diffusion resistantso that the fuel, which is a mixture of organic compounds like thesynthetic resin housing, would not leak or diffuse through the housingand escape into the environment. From a practical point of view both theleakage rate and the diffusion rate should be ideally zero. Toaccomplish this, in the past, the housing had to be well sealed and ofexpensive construction. Fabrication was time-consuming and expensive andmounting of the fuel filter was likewise a problem. Special space had tobe provided in the engine compartment of the vehicle to accommodate thefilter and this was not always available. In the mounted position, thefuel filter was not always accessible readily and could not be openedand closed with absolute reliability. Security against leakage, botharound the cover and by diffusion through the walls of the housing leftmuch to be desired and decreased with time to the point that it did notsatisfy modern needs, legal requirements or desires.

OBJECTS OF THE INVENTION

It is, therefore, the principal object of my present invention toprovide an improved internal combustion engine apparatus for a motorvehicle, including a fuel filter, whereby these drawbacks are avoided.

Another object of the invention is to provide a system for the purposesdescribed which can be fabricated and mounted at lower cost and withless effort, and which affords satisfactory long-term protection of theenvironment with respect to leakage and diffusion.

Still another object of the invention is to provide an improved fuelfilter and system accommodating same which can satisfy all legalrequirements even on a long-term basis for protecting the environmentagainst leakage or diffusion.

It is also an object of this invention to overcome the drawbacks ofearlier systems as described.

Finally, it is an object of the invention to provide an improved fuelfilter system which allows ready access to the cartridge for replacementthereof.

SUMMARY OF THE INVENTION

These objects and others which will become apparent hereinafter areattained, in accordance with the invention, by disposing the fuel filterin one of the components of the fuel-supply system or the air-supplysystem in such manner that any fuel escaping from the fuel filter canonly collect in that component of the system so that leakage fuel orfuel which diffuses from the housing is collected in the aforementionedcomponent and cannot, therefore, escape into the environment.

According to the invention, the problem of leakage between the cover andbody of the housing is in part solved by the following combination offeatures:

(a) The fuel filter has a fuel filter housing, at least one filtercartridge received in the housing and arranged to be replaced thereinand a cover which is removable from the housing to afford access to thefilter cartridge for replacing same.

(b) Between the cover and the fuel filter housing there is formed a gap,clearance or space which permits fuel to accumulate and thus collectsany leakage between the cover and the housing.

(c) There is provided between this space and the fuel-supply systemand/or the air-supply system a passage enabling that space to drain intoone or both of the aforementioned systems so that leakage does notescape into the environment.

In a preferred embodiment of the invention, the cover is formed as aninset into the housing and has a collar juxtaposed with a wall of themouth of the housing to define the aforementioned gap or spacetherewith, and a cover flange which is affixed to that collar andoverlies a shoulder of the housing surrounding the mouth thereof. Thecollection space can thus be formed between the collar and thejuxtaposed filter housing wall and between the cover flange and theshoulder, this space being connected by at least one bore with thefuel-supply system or the air system.

The cover is affixed to the fuel filter housing by screwing a clampingnut onto a threaded neck of the fuel filter housing, the nut overlyingthe flange. While sealing rings are not absolutely essential inaccordance with the invention, a sealing ring may be provided betweenthe collar and the juxtaposed seal of the housing while another sealingring can be provided between the flange and the housing. The rings maybe O-rings received in outwardly open recesses of the collar and theflange, respectively. According to yet another feature of the invention,the fuel filter is mounted in the fuel tank of the vehicle with itscover externally accessible. In that case, the collecting space is incommunication with the interior of the fuel tank and any leakage can bedrained back into the fuel tank. The fuel filter can be mounted in theactive carbon filter of an air-venting system associated with theair-supply system and here also has an outwardly-disposed cover. Thecollecting space is here in communication with a collecting space forthe fuel vapor. From the latter collecting space a suction line can runto the engine of the motor vehicle.

In a further embodiment, the fuel filter is incorporated into thecombustion air filter of the air-supply system and has anoutwardly-disposed cover affording access to the replaceable filter. Thespace here communicates with a collecting chamber in the direction offlow of the combustion air behind the filter body of the air filter sothat leakage is drained into this region.

The filter may then be composed of a synthetic resin filter housingwhich has reduced blocking effect against escape into the environment orreduced security against leakage. The fuel filter can then satisfy lawsand regulations regarding environment protection only after it has beenbuilt into one of the components of the fuel-supply or air-supplysystems.

The fuel filter can be mounted directly in a wall of the fuel tank or inthe active carbon filter of the tank venting unit from which the suctionline can run to the engine. It can be incorporated in the air filter ofthe air-supply system. Regardless of the component into which it isbuilt, the cover should be accessible along the outer wall of thatcomponent to enable the cover to be removed, the filter cartridge to beaccessed and the replacement to be effected. Special cover sealingarrangements are not required. The fuel filter can be formed as amodular component with a fuel filter sealing injection molded fromthermoplastic synthetic resin material with its internal fittings formedunitarily therewith. The cover can also be injection molded fromthermoplastic material. The fuel filter housing and the cover can bediffusion-tight and can be composed, if desired, of multilayered plasticwith certain of the layers forming barriers against diffusion of thefuel out of the housing or diffusion of the fuel components through thehousing. It is also possible, however, to tolerate significant diffusionrates when the filter is built into one of the components of the airsupply or fuel system as described.

The invention basically recognizes that it is difficult, if notimpossible, to completely prevent diffusion or mechanical leakage offuel from a filter housing, especially when the fuel is under pressureand provides in a simple and economical way, protection againstpollution of the environment with the fuel by enabling components whichnormally contain fuel to capture any leakage or diffusing fuel. Thecapture or evacuation of the fuel from the component is effected throughthe conventionally-provided suction line to the engine, for example, orby draining the leakage back into the fuel tank so that it will becombusted in the normal course of operation of the engine. As aconsequence, the invention satisfies all environmental regulations andlaws.

Since the integration of the fuel filter in the components is simple,the invention can be practiced at low cost.

The internal combustion engine apparatus for a motor vehicle can thuscomprise:

an internal combustion engine;

a fuel-supply system for the internal combustion engine comprising:

a fuel tank component,

a fuel pump component for pumping fuel from the fuel tank component tothe engine, and

a fuel line connected with the fuel tank component and the fuel linecomponent for feeding pumped fuel to the engine;

an air-supply system comprising:

an air filter component, and

an air duct connected with the air filter and with the engine forfeeding air to the engine;

a fuel filter connected in a path of fuel supplied by the pump to theengine and comprising:

a fuel-filter housing composed of a synthetic resin material anddisposed in one of the components of a respective one of the systems sothat uncontrolled escape of fuel from the fuel-filter housing iscaptured in the one of the components, and

a replaceable filter cartridge in the fuel-filter housing and traversedby the fuel as the fuel travels along the path under a pressure of thefuel generated in the housing by the fuel pump component.

BRIEF DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages of the inventionwill become more readily apparent from the following description,reference being made to the accompanying highly diagrammatic drawing inwhich:

FIG. 1 is a vertical section through an apparatus according to theinvention in which the fuel filter is incorporated in a wall of the fueltank;

FIG. 1A is a detail view of the region IA of FIG. 1 drawn to a largerscale;

FIG. 2 is a vertical section through an active carbon filter in a fueltank forming part of the tank venting system and in which a fuel filteris provided;

FIG. 3 is an elevational view showing a fuel filter in the air-supplysystem of a motor vehicle;

FIG. 4 is a section taken along the line IV--IV of FIG. 3 drawn to alarger scale; and

FIG. 5 is a perspective view diagrammatically illustrating the fuel andair-supply system for an internal combustion engine according to theinvention.

SPECIFIC DESCRIPTION

Referring first to FIG. 5, it will be apparent that the drive system fora motor vehicle can include an internal combustion engine 30 whosecrankshaft 31 can be connected to a transmission and the wheel drivemechanism of the vehicle. The engine 30 has an exhaust manifold systemrepresented at 32, spark plugs 33 and an air-feed system including anintake manifold 34 with feeders 35 communicating with the intake portsof-the engine. The intake manifold is connected by the air-supply duct36 with an air filter 37 having an externally-accessible housing wall 38in which the fuel filter can be provided in the manner described. Thevehicle also has a fuel tank 39 with a filler pipe 40 through which thefiller can be supplied to the tank. A fuel pump 41 can feed the fuel andthe fuel-supply system further comprises a fuel line 42 which deliversthe fuel to the fuel injector system represented diagrammatically at 43.The tank 39 can be provided with a venting filter 44 of a tank-ventingsystem connected by a suction pipe 45 to the intake manifold so that thefumes from the tank are fed to the cylinder of the engine with the airsupplied thereto. The dot-dash line 45 represents a path of the fuel andis intended to indicate that, along the path between the pump and thefuel injection system, a filter is provided as described in connectionwith FIGS. 1 and 1A, FIG. 2 or FIGS. 3 and 4. As can be seen from theseFigures, the basic construction of a fuel filter 1 is that of a filterhousing 6 and a replaceable cartridge 7 received therein. That filter 1can be provided in or on the fuel tank component 2 of the fuel system(FIGS. 1 and 1A), in or on the tank venting unit 19 shown in FIG. 2 ofthe air-supply system or in or on the air filter 4 shown in FIG. 3.

In FIGS. 1 and 1A, the fuel filter 1 is shown to be mounted in the fueltank 20 and to be connected by the fuel line 3 to the internalcombustion engine. FIG. 3 shows that the air system has an air filter 4and an air duct 5 for the combustion air.

As previously described, the fuel filter 1 has a housing 6 composed ofthermoplastic synthetic resin and receiving the replaceable filtercartridge 7. To allow removal of the filter cartridge 7, a removablecover 8 is mounted on the housing 6. Between the cover 8 and the housing6 there is provided a gap or spacing 9 which corrects leakage fuel andwhich is connected in turn by a passage 10 with the interior of thecomponent on which the filter is mounted so that the gap 9 is incommunication with the interior of this component of the fuel-supplysystem and/or the air system in a manner preventing external leakage.The fuel filter housing 6 and the cartridge 7 are at superatmosphericpressure when the fuel pump 11 is turned on.

In one embodiment and in the preferred embodiment of the invention thecover 8 of the fuel filter housing 6 is an inset cover with a collar 12and a flange 13, the flange covering resting upon a shoulder 14 of thefilter housing 6. This space or gap 9 is provided between the collar 12and the juxtaposed wall of the filter housing 6 and between the flange13 and the shoulder 14, the gap or space 9 being connected by at leastone bore with the fuel system or the air system.

The cover 6 is held forcibly against the shoulder 14 of the housing by aclamping nut 15 threaded onto a mouth 50 of the housing 6. In the gap 9,two sealing rings 16 can be provided, at least one of these rings beingreceived in a recess 17 of the cover 6. In the embodiment of FIGS. 1 and2, the upper sealing ring 16 may suffice and indeed the sealing ringsmay be completely eliminated if desired.

In the embodiment of FIG. 1, the filter 1 is located in the fuel tank 2with its cover 8 being accessible from the exterior and the correctionspace 9 connected with the interior of the fuel tank in a leak-tightmanner.

In the embodiment of FIG. 2 the fuel filter 1 is disposed in the activecarbon filter 18 of the tank venting system 19 with its cover 8 lyingexternally and this readily accessible. Here the space 9 communicateswith a collecting compartment 20 for the fuel vapors in a leak-tightmanner. From the collecting chamber 20, a suction line 21 runs to theengine and can correspond to the line 45.

In the embodiment of FIGS. 3 and 4, the fuel filter 1 is disposed in thecombustion air filter 4 of the air system with an externally disposedcover. The gap or space 9 is here in communication with the collectingchamber 22 which is located behind the filter body 23 in the flowdirection of the combustion air.

It will be apparent that the fuel filter 1 shown in FIGS. 1-4 and thehousing 6 of it are cylindrical. By comparison of FIGS. 1-3, the modularconstruction will be apparent. The housing 6 is injection molded ofthermal plastic synthetic resin and comprises injection-moldedcomponents. The cover 6 is also of thermoplastic synthetic resin. In allcases any leakage from the fuel filter is collected or captured by oneof the components of the systems described. When the filter housing 6 isnot highly diffusion resistant or there is a reduced blockage or barriereffect to diffusion or locations of leakage arise, the leaking fuel isalways collected and prevented from reaching the environment in adetrimental manner.

I claim:
 1. An internal combustion engine apparatus for a motor vehicle,said apparatus comprising:an internal combustion engine; a fuel-supplysystem for said internal combustion engine comprising:a fuel tankcomponent, a fuel pump component for pumping fuel from said fuel tankcomponent to said engine, and a fuel line connected with said fuel tankcomponent and said fuel line component for feeding pumped fuel to saidengine; an air-supply system comprising:an air filter component, and anair duct connected with said air filter and with said engine for feedingair to said engine; a fuel filter connected in a path of fuel suppliedby said pump to said engine and comprising:a fuel-filter housingcomposed of a synthetic resin material and disposed in one of saidcomponents of a respective one of said systems but separate from therespective one of said components so that uncontrolled escape of fuelfrom said fuel-filter housing is captured in said one of saidcomponents, a replaceable filter cartridge in said fuel-filter housingand traversed by said fuel as said fuel travels along said path under apressure of said fuel generated in said housing by said fuel pumpcomponent, and a removable cover fitted onto said housing and affordingaccess to said replaceable filter cartridge.
 2. The apparatus defined inclaim 1 wherein said fuel filter further comprises:means defining aleakage-collecting space between said cover and said fuel-filter housingfor collecting fuel leaking from said fuel-filter housing; and meansconnecting said space with said one of said components for deliveringcollected fuel leaking from said housing to said one of said components.3. The apparatus defined in claim 2 wherein said cover is fitted intosaid housing and comprises a collar extending into a cover openingformed in said housing, and an annular flange overhanging said opening,said flange forming a seal with a juxtaposed shoulder of said housingsurrounding said opening, said space being located inwardly of said sealaround said collar, said housing having at least one bore connectingsaid space with said one of said components.
 4. The apparatus defined inclaim 3, further comprising a clamping nut threaded onto said housing,overlying said flange and holding said flange against said shoulder. 5.The apparatus defined in claim 3, further comprising a sealing ringreceived in a recess in said collar and engaging said housing in saidspace.
 6. The apparatus defined in claim 3, further comprising a sealingring between said flange and said housing.
 7. The apparatus defined inclaim 2 wherein said fuel filter is located in said fuel-tank componentwith said cover accessible from a location external of said tankcomponent.
 8. The apparatus defined in claim 7 wherein said air-supplysystem includes a tank vent in said tank connected with said engine todraw fumes from said tank component, said filter being received in saidvent and emptying said space into a collecting compartment of said ventfor fuel vapors, said compartment being connected to said engine.
 9. Theapparatus defined in claim 2 wherein said fuel filter is located in saidair-filter component with said cover accessible from a location externalof said air-filter component, said space communicating with an interiorof said air-filter component at a location behind a filter body thereof.10. The apparatus defined in claim 2 wherein said fuel filter is formedas a modular unit with the housing injection molded of thermoplasticsynthetic resin with internal structures, said cover being injectionmolded of thermoplastic synthetic resin.
 11. The apparatus defined inclaim 1 wherein said housing is composed of a plastic of limited utilityin preventing fuel leakage and protection of the environment againstfuel leakage is effected by incorporating said housing in said one ofsaid components.
 12. The apparatus defined in claim 11 wherein saidhousing is built into said tank component.
 13. The apparatus defined inclaim 11 wherein said fuel filter is built into an active carbon filterventing an interior of said tank component to said engine through asuction line.
 14. The apparatus defined in claim 11 wherein said fuelfilter is built into said air-filter component.
 15. The apparatusdefined in claim 11 wherein said fuel filter is built into an outer wallof said one of said components and has a cover which closes an openingthrough which said filter cartridge is accessible.
 16. The apparatusdefined in claim 15 wherein said fuel filter is formed as a modular unitwith the housing injection molded of thermoplastic synthetic resin withinternal structures, said cover being injection molded of thermoplasticsynthetic resin.